Andrena micheneriella

Justification:
Andrena micheneriella is a solitary bee that is known from just four observations. It has been recorded from the San Antonio vicinity of Texas, United States. Existing records are accompanied by ambiguous geodata, and the exact number of localities is not clear. Because of this, it is not possible to calculate an extent of occurrence (EOO). The EOO is expected to be less than 3,250 km2, which is the total area of Bexar County. Additionally, this species has not been recorded since 1998. Three of the four records of this species come from the 1950s. It is not clear if the species is still extant. There is little information about the habitat and ecology of this species. It has been recorded foraging from two genera from the plant family Asteraceae, but its dietary breadth is not known. Specific threats to this species have not been identified. It may be subject to threats facing other bees generally, such as habitat loss, climate change, and exposure to pesticides. More information is needed to determine if this species is still extant, and to better understand its biology. Because this species cannot be confirmed to occur in more than two localities, and is known from few records overall with little available information about its life history, it is assessed as Data Deficient for now.

Food habits comment: Andrena micheneriella has been recorded foraging from plants in the genera Baccharis and Aster (Asteraceae) (LaBerge 1967). There is not enough information about this species to determine its dietary breadth. Habitat comment: Because of limited records of this species and the geographic uncertainty of existing localities of this species, its habitat is not well understood. All records likely come from Northern Blackland Prairie, which is made up of several habitat types. Reproduction comment: This species likely nests underground like all other Andrena (Danforth et al. 2019), but nests from this species have not been described. Nest cells from other members of this genus are located at the ends of the lateral burrows, which are typically lined with a waxy Dufour’s gland secretion (Cane 1981) that serves to both isolate the provision from pathogens in the surrounding soil and to regulate water uptake from the soil atmosphere (Cane and Love 2021). Females provision each cell with a ball of pollen moistened with nectar on which they lay a single egg (Michener 2007). Phenology comment: Records of this species come from October and November (Chesshire et al. 2023). Adults are assumed to emerge annually (Danforth et al. 2019).

Threat comments: Specific threats to this species have not been directly investigated. Certain aspects of this species' biology may make it more vulnerable to some threats. Andrena micheneriella is a ground nesting species, and nests may be harmed by certain agricultural practices such as tilling, which can kill bees nesting close to the surface (Williams et al. 2010). Additionally, Andrena have been reported to have low reproductive output because of the short adult life span, and a low rate of brood cell provisioning (reviewed in Danforth et al. 2019). Other threats to bees generally include habitat loss or modification, climate change, pesticide use, exposure to pathogens from managed bee species, and competition with honey bees (Brown and Paxton 2009; Potts et al. 2010; Wojcik et al. 2018; Grab et al. 2019; Raven and Wagner 2021). Threats Threats: Timing: Scope: Severity: Impact Score: 1. Residential & commercial development -> 1.1. Housing & urban areas 1. Residential & commercial development -> 1.2. Commercial & industrial areas 2. Agriculture & aquaculture -> 2.1. Annual & perennial non-timber crops -> 2.1.3. Agro-industry farming 7. Natural system modifications -> 7.1. Fire & fire suppression -> 7.1.1.Increase in fire frequency/intensity 7. Natural system modifications -> 7.1. Fire & fire suppression -> 7.1.2. Suppression in fire frequency/intensity 8. Invasive and other problematic species, genes, and diseases -> 8.1 Invasive non-native/alien species/diseases -> 8.1.2. Named species 9. Pollution -> 9.3 Agricultural and forestry effluents -> 9.3.3 Herbicides and Pesticides 11. Climate change & severe weather -> 11.1. Habitat shifting & alteration 11. Climate change & severe weather -> 11.2.Droughts 11. Climate change & severe weather -> 11.3.Temperature extremes Conservation Actions Conservation needs No known conservation actions are in place for this species. Protected/Managed area comment: There are no observations of this species from any protected or managed areas. Management comment: Specific conservation needs for this species have not been identified. Due to the importance of supporting wild bee populations for pollination services, general conservation practices are recommended including, restoring, creating, and preserving natural high-quality habitats to include suitable forage and nesting sites; limiting pesticide use on or near suitable habitat, particularly during the adult bee’s flight period; promoting farming and urban practices that increase pollinator-friendly plants in margin space; minimizing exposure of wild bees to diseases transferred from managed bees; and lastly, avoiding honey bee introduction to high-quality native bee habitat. Conservation Actions Needed 1. Land/water protection -> 1.2. Resource & habitat protection 2. Land/water management -> 2.3. Habitat & natural process restoration 4. Education & awareness -> 4.3. Awareness & communications 5. Law & policy -> 5.2. Policies and regulations Research needs Research need comment: More information is needed about the population status, population trend, existing threats, range limits, habitat, and ecology of this species. Surveys targeting this species are needed throughout its range to determine its persistence throughout its historic range. Research Needed 1. Research -> 1.2. Population size, distribution & trends 1.3. Life History and Ecology 1.5. Threats 1.6 Conservation actions 3. Monitoring -> 3.1. Population trends 3.4. Habitat trends Assessment Date of assessment (month-day-year): 8-11-2025 Assessors names (use * to indicate primary assessor, typically the participant with most experience/knowledge of the species): Saff Killingsworth Reviewer(s): Contributors(s): For a full list of the 162 institutions that contributed to the Chesshire et al. dataset, please see Chesshire et al. 2023, S1. Facilitator(s) and compiler(s): Paige R. Chesshire, Erica E. Fischer, Nicolas J. Dowdy, Terry L. Griswold, Alice C. Hughes, Michael C. Orr, John S. Ascher, Laura M. Guzman, Keng-Lou James Hung, Neil S. Cobb and Lindsie M. McCabe Red List Category and Criteria: Data Deficient Justification: Andrena micheneriella is a solitary bee that is known from just four observations. It has been recorded from the San Antonio vicinity of Texas, United States. Existing records are accompanied by ambiguous geodata, and the exact number of localities is not clear. Because of this, it is not possible to calculate an extent of occurrence (EOO). The EOO is expected to be less than 3,250 km2, which is the total area of Bexar County. Additionally, this species has not been recorded since 1998. Three of the four records of this species come from the 1950s. It is not clear if the species is still extant. There is little information about the habitat and ecology of this species. It has been recorded foraging from two genera from the plant family Asteraceae, but its dietary breadth is not known. Specific threats to this species have not been identified. It may be subject to threats facing other bees generally, such as habitat loss, climate change, and exposure to pesticides. More information is needed to determine if this species is still extant, and to better understand its biology. Because this species cannot be confirmed to occur in more than two localities, and is known from few records overall with little available information about its life history, it is assessed as Data Deficient for now. Rank reasons This species is a solitary bee that is known from just four observations. It has been recorded from the San Antonio vicinity of Texas, United States. Existing records are accompanied by ambiguous geodata, and the exact number of localities is not clear. Because of this, it is not possible to calculate a range extent. The range extent is expected to be less than 3,250 km2, which is the total area of Bexar County. Additionally, this species has not been recorded since 1998. Three of the four records of this species come from the 1950s. It is not clear if the species is still extant. There is little information about the habitat and ecology of this species. It has been recorded foraging from two genera from the plant family Asteraceae, but its dietary breadth is not known. Specific threats to this species have not been identified. It may be subject to threats facing other bees generally, such as habitat loss, climate change, and exposure to pesticides. More information is needed to determine if this species is still extant, and to better understand its biology. Because this species cannot be confirmed to occur in more than two localities, and is known from few records overall with little available information about its life history, it is unranked for now.. NatureServe Specific Text (NOT OTHERWISE INCLUDED IN ABOVE TEXT): For Rank Calculator: 1. Element occurrences (using separation distance of 5,000 m): 1 1. Estimated Number of Element Occurrences Comments: Only one element occurrence of this species using a 5 km separation distance has been recorded using all records from the last 30 years (since 1995). The number of element occurrences overall is not well understood due to poor quality geodata. 2. Population size: Unknown 3. Viability/Ecological integrity (choose one) 1. Number of occurrences with good viability/ecological integrity: Unknown 2. Percent of area occupied (For Species with Known AOO): N/A 4. Environmental Specificity: Unknown 1. Environmental specificity comments: There is not enough information about this species to determine its environmental specificity, although it may have specific habitat needs that are not yet understood. 5. Intrinsic Vulnerability: B. Moderately vulnerable 1. Intrinsic vulnerability comments: Andrena have been reported to have low reproductive output because of the short adult life span, and a low rate of brood cell provisioning (reviewed in Danforth et al. 2019). 6. Trend 1. Short Term Trend: Unknown 2. Comments: Abundance estimates and population trends are not known for this species. 3. Long Term Trend: Unknown 4. Comments: Abundance estimates and population trends are not known for this species. For Biotics Global Element Characterization: 1. Habitat Unknown 2. Food Habits 1. Adult: nectarivore 2. Immature: nectarivore Literature References: Brown, Mark J. F., and Robert J. Paxton. 2009. “The Conservation of Bees: A Global Perspective.” Apidologie 40 (3): 410–16. Cane, James H., and Byron G. Love. 2021. “Hygroscopic Larval Provisions of Bees Absorb Soil Water Vapor and Release Liquefied Nutrients.” Apidologie 52 (6): 1002–16. Cane, J. H. 1981. “Dufour’s Gland Secretion in the Cell Linings of Bees (Hymenoptera: Apoidea).” Journal of Chemical Ecology 7 (2): 403–10. Chesshire, Paige R., Erica E. Fischer, Nicolas J. Dowdy, Terry L. Griswold, Alice C. Hughes, Michael C. Orr, John S. Ascher, et al. 2023. “Completeness Analysis for over 3000 United States Bee Species Identifies Persistent Data Gap.” Ecography, February. https://doi.org/10.1111/ecog.06584. Danforth, Bryan N., Robert L. Minckley, John L. Neff, and Frances Fawcett. 2019. The Solitary Bees: Biology, Evolution, Conservation. Princeton University Press. Grab, Heather, Michael G. Branstetter, Nolan Amon, Katherine R. Urban-Mead, Mia G. Park, Jason Gibbs, Eleanor J. Blitzer, Katja Poveda, Greg Loeb, and Bryan N. Danforth. 2019. “Agriculturally Dominated Landscapes Reduce Bee Phylogenetic Diversity and Pollination Services.” Science 363 (6424): 282–84. LaBerge, Wallace E. 1967. “A Revision of the Bees of the Genus Andrena of the Western Hemisphere. Part I. Callandrena. (Hymenoptera: Andrenidae).” Bulletin of the University of Nebraska State Museum 7 (October). http://digitalcommons.unl.edu/museumbulletin. Michener, Charles Duncan. 2007. The Bees of the World. Vol. 1. JHU Press. Potts, Simon G., Jacobus C. Biesmeijer, Claire Kremen, Peter Neumann, Oliver Schweiger, and William E. Kunin. 2010. “Global Pollinator Declines: Trends, Impacts and Drivers.” Trends in Ecology & Evolution 25 (6): 345–53. Raven, Peter H., and David L. Wagner. 2021. “Agricultural Intensification and Climate Change Are Rapidly Decreasing Insect Biodiversity.” Proceedings of the National Academy of Sciences of the United States of America 118 (2). https://doi.org/10.1073/pnas.2002548117. Rousseau, Josée S., S. Hollis Woodard, Sarina Jepsen, Brianne Du Clos, Alison Johnston, Bryan N. Danforth, and Amanda D. Rodewald. 2024. “Advancing Bee Conservation in the US: Gaps and Opportunities in Data Collection and Reporting.” Frontiers in Ecology and Evolution 12. https://doi.org/10.3389/fevo.2024.1346795. Williams, A. Park, B. I. Cook, and S. E. Smerdon. 2022. “Rapid Intensification of the Emerging Southwestern North American Megadrought in 2020–2021.” Nature Climate Change 12 (3): 232–34. Williams, N. M., Elizabeth E. Crone, T’ai H. Roulston, Robert L. Minckley, Laurence Packer, and Simon G. Potts. 2010. “Ecological and Life-History Traits Predict Bee Species Responses to Environmental Disturbances.” Biological Conservation 143 (10): 2280–91. Wojcik, Victoria A., Lora A. Morandin, Laurie Davies Adams, and Kelly E. Rourke. 2018. “Floral Resource Competition Between Honey Bees and Wild Bees: Is There Clear Evidence and Can We Guide Management and Conservation?” Environmental Entomology 47 (4): 822–33.

Conservation needs No known conservation actions are in place for this species. Protected/Managed area comment: There are no observations of this species from any protected or managed areas. Management comment: Specific conservation needs for this species have not been identified. Due to the importance of supporting wild bee populations for pollination services, general conservation practices are recommended including, restoring, creating, and preserving natural high-quality habitats to include suitable forage and nesting sites; limiting pesticide use on or near suitable habitat, particularly during the adult bee’s flight period; promoting farming and urban practices that increase pollinator-friendly plants in margin space; minimizing exposure of wild bees to diseases transferred from managed bees; and lastly, avoiding honey bee introduction to high-quality native bee habitat.

Research need comment: More information is needed about the population status, population trend, existing threats, range limits, habitat, and ecology of this species. Surveys targeting this species are needed throughout its range to determine its persistence throughout its historic range.

This species has been described under the synonym Andrena humeralis.